Improvement in balanced valves



w. n. ANDREWS.

BALANCE!) VALVE.

NPETERS, PNDYO-UTKOGRAPHER. WASHINGTON, D CA Fria.

WILLIAM D. ANDREWS, OF BROOK HAVEN, NEW YORK.

IMPROVEMENT IN BALANCED VALVES.

Specification forming part of Letters Patent No, 175,894, dated April11, i876; application filed July 1, 1875.

To all whom it may concern:

Be it known that I, WILLIAM D. ANDREWS, of Brook Haven, in the county oiSu'olk and State of New York, have invented certain new and usefulImprovements in Reversing Balance Slide-Valves of Steam and otherEngines; and I do hereby declare that the following is a full, clear,and exact description of the same, reference being had to theaccompanying drawing, which forms a part of this specification.

The invention is more particularly designed to be used as areversing-valve, in connection with the main valve of an engine. A valveconstructed in accordance with it is balanced in its action, and isnearly, if not wholly, free from leakage; also works with the mostperfect freedom. Such valve will be found of great advantage in enginesfor working hoisting apparatus.

The invention consists in a novel construction of a hollow valve, thecylinder or casein which the valve works, and the ports and passagespertaining to said valve, the Whole being combined as hereinafterdescribed.

In the accompanying drawing, Figure 1 is -a longitudinal, .partlysectional, view of the valve, taken mainly as indicated by the line a:a' Fig. 2, an exterior longitudinal view of the same 5 and Fig. 3 alongitudinal section 'thereof in a plane at right angles to Fig. l.

let to the valve-case, and the openings D auch E, as connecting,respectively, with the in-` duction and eduction pipes or passages ofthe engine.

The valve B, which may be worked by a rod, f, arranged to pass outthrough a stud'- ing box, g, at the one end of the valve-case, hasrecesses h h around its outer perimeter, and any number of ports itthrough it at such recessed portions, and of an area in the aggregatecorresponding with said recesses. The distances between these recesses h71. is the same as between the channels @and d, and c and c,respectively.

F is a general exhaust passage or outlet, in communication by end orbranch passages 1 F2 with opposite ends of the valve-case A. rIhesepassages Fl F2 are alternately or respectively putin communication bythe adjustment of the valve with the openings D and E, according to thedirection in which it is required torun the engine.

When the valve B is in the position shown in the drawing, the steamentering at O passes around the channel c and recess h, and through theports t' into the interior of the valve, and

from thence through the ports i', recess h', and channel e into theopening E leading to the engine, from which latter, when exhausting, itenters the valve-case A at the opening D, and from thence through thebranch passage F1 to the general outlet F. 'So long as the valve Bremains in this position, the engine will continue to run in the same orforward direction.

To stop the engine, the valve B is moved so as to bring it in closedposition at its longitudinal center over the channel cor steam-inlet Oconnected therewith. The steam then is entirely shut off from the valveand' both openings D and E to the engine are closed, which causes thesteam to cushion on one side of the engine-piston, and a vacuum to formon the opposite side thereof, thereby rapidly arresting the motion ofthe engine without shock or jar. This makes the valve peculiarlyapplicable to engines used for elevating purposes.`

To reverse the engine, the valveB is moved to bring the ports ifincommunication with the steam-inlet G and the ports a' in communicationwith the opening D, so that'steam will pass from the valve through theports t into the channel d, and from thence through the opening D to theengine. In this position of the valve B, the opening E is in freecommunication through the end or branch passage F2 with the outlet F forescape of the exhaust steam from the engine.

By the extension of the channel o entirely around the valve B, thepressure of the steam upon the valve is perfectly balanced,V both valvecase of cast-iron, and the valve of brass, whereby there is very littleWear, and the valve remains tight and will act as a perfect Vstop afteran exceedingly-prolonged use, in-

volving many thousand movements, but at the same time will he perfectlyfree and easy in its movement.

I claim- The combination of the openings G, D, and E, the valve-case A,and its channels or passages c d e, the passages F1 F2, the outlet F,and the single cylindrical hollow valve B, With its lateral ports fi i',essentially as shown and described.

WM. D. ANDREWS. Witnesses:

v HENRY T. BROWN, MICHAEL Rvflv.Y

